In general, for nearly every type of sensor, the temperature of the sensor affects the sensor's performance including the sensing capability, the sensor output, or both. While in some sensor implementations, this influence can be deemed negligible, and therefore ignored, for many precision sensors changes to the sensor performance resulting from the effects of temperature can be a critical performance consideration. In the field of MEMS sensors, including micromachined sensors, for instance, this temperature effect is most often, but not exclusively, seen at the sensor output. In many instances, temperature changes adversely affect the material properties of the sensor with resulting sensor inaccuracy.
In an attempt to compensate for these inaccuracies, many temperature compensation techniques have been developed. The simplest among these is the use of a temperature sensor whose output can be used to compensate for the output of the main or primary sensor. For instance, a temperature sensor can be used to determine the temperature of a pressure sensor (the primary sensor) being used to detect pressures. Most temperature sensors used for such purposes, however, suffer from an inability to provide an accurate temperature of the primary sensor or an inability to provide a desired resolution of the temperature of the primary sensor. The location of the temperature sensor with respect to the primary sensor can also lead to inaccurate sensing of the temperature of the primary sensor.
Temperature sensors are available with a wide range of performance characteristics, including accuracy and resolution. Neglecting the practical aspects of implementing such sensors, the most common problem with such sensors is the inability to place the temperature sensor in sufficiently close proximity to the primary sensor so as to leverage the temperature sensor's performance. Even moderate distances between the temperature sensor and the primary sensor can lead to a thermal lag where thermal lag is defined as a time delay between the occurrence of an actual or real temperature and the measured temperature. Thermal gradients (slightly different temperatures occurring across the location of the sensor) can occur and the temperature across a gradient often cannot be accurately determined. In addition, many implementations of localized temperature sensors can suffer from relatively poor resolution.
Consequently, there is a need for determining the temperature at a primary sensor with improved accuracy and/or resolution. There is a further need to provide a primary sensor having improved performance.